freebsd-dev/sys/kern/kern_shutdown.c
John Baldwin e485b64b08 Add ability to dump stacktraces on kernel panics when DDB is compiled into
the kernel.  By default this is turned off since otherwise it could scroll
valuable panic messages off of the screen.  This option can be turned on
by the DDB_TRACE kernel option as well as the debug.trace_on_panic sysctl.

Also, fix the DDB_UNATTENDED option to use its own header instead of
abusing opt_ddb.h.  This way turning that one option on or off doesn't
force you to recompile all of ddb.

Requested by:	many (1), bde (2*)

* - I know bde prefers !abusing option headers in general but can't
    remember if he as brought up this specific case.
2002-09-19 18:49:46 +00:00

583 lines
14 KiB
C

/*-
* Copyright (c) 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_shutdown.c 8.3 (Berkeley) 1/21/94
* $FreeBSD$
*/
#include "opt_ddb.h"
#include "opt_ddb_trace.h"
#include "opt_ddb_unattended.h"
#include "opt_hw_wdog.h"
#include "opt_panic.h"
#include "opt_show_busybufs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/disklabel.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/resourcevar.h>
#include <sys/smp.h> /* smp_active */
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/vnode.h>
#include <machine/pcb.h>
#include <machine/md_var.h>
#include <machine/smp.h>
#include <sys/signalvar.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#ifndef PANIC_REBOOT_WAIT_TIME
#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
#endif
/*
* Note that stdarg.h and the ANSI style va_start macro is used for both
* ANSI and traditional C compilers.
*/
#include <machine/stdarg.h>
#ifdef DDB
#ifdef DDB_UNATTENDED
int debugger_on_panic = 0;
#else
int debugger_on_panic = 1;
#endif
SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
&debugger_on_panic, 0, "Run debugger on kernel panic");
#ifdef DDB_TRACE
int trace_on_panic = 1;
#else
int trace_on_panic = 0;
#endif
SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
&trace_on_panic, 0, "Print stack trace on kernel panic");
#endif
int sync_on_panic = 1;
SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
&sync_on_panic, 0, "Do a sync before rebooting from a panic");
SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
#ifdef HW_WDOG
/*
* If there is a hardware watchdog, point this at the function needed to
* hold it off.
* It's needed when the kernel needs to do some lengthy operations.
* e.g. in wd.c when dumping core.. It's most annoying to have
* your precious core-dump only half written because the wdog kicked in.
*/
watchdog_tickle_fn wdog_tickler = NULL;
#endif /* HW_WDOG */
/*
* Variable panicstr contains argument to first call to panic; used as flag
* to indicate that the kernel has already called panic.
*/
const char *panicstr;
int dumping; /* system is dumping */
static struct dumperinfo dumper; /* our selected dumper */
static struct pcb dumppcb; /* "You Are Here" sign for dump-debuggers */
static void boot(int) __dead2;
static void poweroff_wait(void *, int);
static void shutdown_halt(void *junk, int howto);
static void shutdown_panic(void *junk, int howto);
static void shutdown_reset(void *junk, int howto);
/* register various local shutdown events */
static void
shutdown_conf(void *unused)
{
EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, SHUTDOWN_PRI_FIRST);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, SHUTDOWN_PRI_LAST + 100);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, SHUTDOWN_PRI_LAST + 100);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, SHUTDOWN_PRI_LAST + 200);
}
SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
/*
* The system call that results in a reboot
*
* MPSAFE
*/
/* ARGSUSED */
int
reboot(struct thread *td, struct reboot_args *uap)
{
int error;
mtx_lock(&Giant);
if ((error = suser(td)) == 0)
boot(uap->opt);
mtx_unlock(&Giant);
return (error);
}
/*
* Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
*/
static int shutdown_howto = 0;
void
shutdown_nice(int howto)
{
shutdown_howto = howto;
/* Send a signal to init(8) and have it shutdown the world */
if (initproc != NULL) {
PROC_LOCK(initproc);
psignal(initproc, SIGINT);
PROC_UNLOCK(initproc);
} else {
/* No init(8) running, so simply reboot */
boot(RB_NOSYNC);
}
return;
}
static int waittime = -1;
static void
print_uptime(void)
{
int f;
struct timespec ts;
getnanouptime(&ts);
printf("Uptime: ");
f = 0;
if (ts.tv_sec >= 86400) {
printf("%ldd", (long)ts.tv_sec / 86400);
ts.tv_sec %= 86400;
f = 1;
}
if (f || ts.tv_sec >= 3600) {
printf("%ldh", (long)ts.tv_sec / 3600);
ts.tv_sec %= 3600;
f = 1;
}
if (f || ts.tv_sec >= 60) {
printf("%ldm", (long)ts.tv_sec / 60);
ts.tv_sec %= 60;
f = 1;
}
printf("%lds\n", (long)ts.tv_sec);
}
static void
doadump(void)
{
savectx(&dumppcb);
dumping++;
dumpsys(&dumper);
}
/*
* Go through the rigmarole of shutting down..
* this used to be in machdep.c but I'll be dammned if I could see
* anything machine dependant in it.
*/
static void
boot(int howto)
{
/* collect extra flags that shutdown_nice might have set */
howto |= shutdown_howto;
#ifdef DDB
/* We are out of the debugger now. */
db_active = 0;
#endif
#ifdef SMP
if (smp_active)
printf("boot() called on cpu#%d\n", PCPU_GET(cpuid));
#endif
/*
* Do any callouts that should be done BEFORE syncing the filesystems.
*/
EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
/*
* Now sync filesystems
*/
if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
register struct buf *bp;
int iter, nbusy, pbusy;
int subiter;
waittime = 0;
printf("\nsyncing disks... ");
sync(&thread0, NULL);
/*
* With soft updates, some buffers that are
* written will be remarked as dirty until other
* buffers are written.
*/
for (iter = pbusy = 0; iter < 20; iter++) {
nbusy = 0;
for (bp = &buf[nbuf]; --bp >= buf; ) {
if ((bp->b_flags & B_INVAL) == 0 &&
BUF_REFCNT(bp) > 0) {
nbusy++;
} else if ((bp->b_flags & (B_DELWRI | B_INVAL))
== B_DELWRI) {
/* bawrite(bp);*/
nbusy++;
}
}
if (nbusy == 0)
break;
printf("%d ", nbusy);
if (nbusy < pbusy)
iter = 0;
pbusy = nbusy;
sync(&thread0, NULL);
if (curthread != NULL) {
DROP_GIANT();
for (subiter = 0; subiter < 50 * iter; subiter++) {
mtx_lock_spin(&sched_lock);
curthread->td_proc->p_stats->p_ru.ru_nvcsw++;
mi_switch(); /* Allow interrupt threads to run */
mtx_unlock_spin(&sched_lock);
DELAY(1000);
}
PICKUP_GIANT();
} else
DELAY(50000 * iter);
}
printf("\n");
/*
* Count only busy local buffers to prevent forcing
* a fsck if we're just a client of a wedged NFS server
*/
nbusy = 0;
for (bp = &buf[nbuf]; --bp >= buf; ) {
if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
if (bp->b_dev == NODEV) {
TAILQ_REMOVE(&mountlist,
bp->b_vp->v_mount, mnt_list);
continue;
}
nbusy++;
#if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
printf(
"%d: dev:%s, flags:%08lx, blkno:%ld, lblkno:%ld\n",
nbusy, devtoname(bp->b_dev),
bp->b_flags, (long)bp->b_blkno,
(long)bp->b_lblkno);
#endif
}
}
if (nbusy) {
/*
* Failed to sync all blocks. Indicate this and don't
* unmount filesystems (thus forcing an fsck on reboot).
*/
printf("giving up on %d buffers\n", nbusy);
DELAY(5000000); /* 5 seconds */
} else {
printf("done\n");
/*
* Unmount filesystems
*/
if (panicstr == 0)
vfs_unmountall();
}
DELAY(100000); /* wait for console output to finish */
}
print_uptime();
/*
* Ok, now do things that assume all filesystem activity has
* been completed.
*/
EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
splhigh();
if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP &&
!cold && dumper.dumper != NULL && !dumping)
doadump();
/* Now that we're going to really halt the system... */
EVENTHANDLER_INVOKE(shutdown_final, howto);
for(;;) ; /* safety against shutdown_reset not working */
/* NOTREACHED */
}
/*
* If the shutdown was a clean halt, behave accordingly.
*/
static void
shutdown_halt(void *junk, int howto)
{
if (howto & RB_HALT) {
printf("\n");
printf("The operating system has halted.\n");
printf("Please press any key to reboot.\n\n");
switch (cngetc()) {
case -1: /* No console, just die */
cpu_halt();
/* NOTREACHED */
default:
howto &= ~RB_HALT;
break;
}
}
}
/*
* Check to see if the system paniced, pause and then reboot
* according to the specified delay.
*/
static void
shutdown_panic(void *junk, int howto)
{
int loop;
if (howto & RB_DUMP) {
if (PANIC_REBOOT_WAIT_TIME != 0) {
if (PANIC_REBOOT_WAIT_TIME != -1) {
printf("Automatic reboot in %d seconds - "
"press a key on the console to abort\n",
PANIC_REBOOT_WAIT_TIME);
for (loop = PANIC_REBOOT_WAIT_TIME * 10;
loop > 0; --loop) {
DELAY(1000 * 100); /* 1/10th second */
/* Did user type a key? */
if (cncheckc() != -1)
break;
}
if (!loop)
return;
}
} else { /* zero time specified - reboot NOW */
return;
}
printf("--> Press a key on the console to reboot,\n");
printf("--> or switch off the system now.\n");
cngetc();
}
}
/*
* Everything done, now reset
*/
static void
shutdown_reset(void *junk, int howto)
{
printf("Rebooting...\n");
DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
/* cpu_boot(howto); */ /* doesn't do anything at the moment */
cpu_reset();
/* NOTREACHED */ /* assuming reset worked */
}
#ifdef SMP
static u_int panic_cpu = NOCPU;
#endif
/*
* Panic is called on unresolvable fatal errors. It prints "panic: mesg",
* and then reboots. If we are called twice, then we avoid trying to sync
* the disks as this often leads to recursive panics.
*
* MPSAFE
*/
void
panic(const char *fmt, ...)
{
struct thread *td = curthread;
int bootopt, newpanic;
va_list ap;
static char buf[256];
#ifdef SMP
/*
* We don't want multiple CPU's to panic at the same time, so we
* use panic_cpu as a simple spinlock. We have to keep checking
* panic_cpu if we are spinning in case the panic on the first
* CPU is canceled.
*/
if (panic_cpu != PCPU_GET(cpuid))
while (atomic_cmpset_int(&panic_cpu, NOCPU,
PCPU_GET(cpuid)) == 0)
while (panic_cpu != NOCPU)
; /* nothing */
#endif
bootopt = RB_AUTOBOOT | RB_DUMP;
newpanic = 0;
if (panicstr)
bootopt |= RB_NOSYNC;
else {
panicstr = fmt;
newpanic = 1;
}
va_start(ap, fmt);
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
if (panicstr == fmt)
panicstr = buf;
va_end(ap);
printf("panic: %s\n", buf);
#ifdef SMP
/* two separate prints in case of an unmapped page and trap */
printf("cpuid = %d; ", PCPU_GET(cpuid));
#ifdef APIC_IO
printf("lapic.id = %08x\n", lapic.id);
#else
printf("\n");
#endif
#endif
#if defined(DDB)
if (newpanic && trace_on_panic)
db_print_backtrace();
if (debugger_on_panic)
Debugger ("panic");
#ifdef RESTARTABLE_PANICS
/* See if the user aborted the panic, in which case we continue. */
if (panicstr == NULL) {
#ifdef SMP
atomic_store_rel_int(&panic_cpu, NOCPU);
#endif
return;
}
#endif
#endif
td->td_flags |= TDF_INPANIC;
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
boot(bootopt);
}
/*
* Support for poweroff delay.
*/
#ifndef POWEROFF_DELAY
# define POWEROFF_DELAY 5000
#endif
static int poweroff_delay = POWEROFF_DELAY;
SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
&poweroff_delay, 0, "");
static void
poweroff_wait(void *junk, int howto)
{
if(!(howto & RB_POWEROFF) || poweroff_delay <= 0)
return;
DELAY(poweroff_delay * 1000);
}
/*
* Some system processes (e.g. syncer) need to be stopped at appropriate
* points in their main loops prior to a system shutdown, so that they
* won't interfere with the shutdown process (e.g. by holding a disk buf
* to cause sync to fail). For each of these system processes, register
* shutdown_kproc() as a handler for one of shutdown events.
*/
static int kproc_shutdown_wait = 60;
SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
&kproc_shutdown_wait, 0, "");
void
kproc_shutdown(void *arg, int howto)
{
struct proc *p;
int error;
if (panicstr)
return;
p = (struct proc *)arg;
printf("Waiting (max %d seconds) for system process `%s' to stop...",
kproc_shutdown_wait, p->p_comm);
error = kthread_suspend(p, kproc_shutdown_wait * hz);
if (error == EWOULDBLOCK)
printf("timed out\n");
else
printf("stopped\n");
}
/* Registration of dumpers */
int
set_dumper(struct dumperinfo *di)
{
if (di == NULL) {
bzero(&dumper, sizeof dumper);
return (0);
}
if (dumper.dumper != NULL)
return (EBUSY);
dumper = *di;
return (0);
}
#if defined(__powerpc__) || defined(__sparc64__)
void
dumpsys(struct dumperinfo *di __unused)
{
printf("Kernel dumps not implemented on this architecture\n");
}
#endif